Ultra high frequency electronic device



'pril l?, 1945. E. G. UNDER Y 2,373,837

ULTRA HIGH FREQUENCY ELECTRONIC DEVCE Filed Oct. 5l, 1941 Fg@ i EG o g y l l (66| 59 o 'mventor l IZ Erneqs @Lw/dar if r l l' b A@19| Bg E LENS 0mm/wwf; +B, Y, mmm

Patented nog. i7? i 1f.

atraer: otros suon raisonner arsenic nevica hoest o. meer, enamorarse, rai., assignee 'to o Corporation oil erica, a corporation oi luelae Anplication OcQbcrSLQdH, Serial No.V jll'l 7 Claims. (C11. 2505-27) This invention relates to improvements in ultra high frequency electronic devices. and particularly to ar. electronic device in which the operating parameters are controlled by an oscillating electriciens.

ln ultra high frequency electronic devices the transit time and the course or path of the electrons are important factors. electron may be altered by subjecting the electron to the iniiuence oi a magnetic or electrostatic held. li the held is appropriately shaped, an electric lens `will be formed. Electrons passing through such a lens willl be focused just as light waves are focused by a conventional lens.

While such electric lenses have been used in electron microscopes, to form images of electron transparent specimens, and in other electronic devices, these lenses are adjusted primarily to obtain a xed focus. invention, means are provided whereby an elec- The path of an' is an object oi the present f tric lens or" oscillatory focal length may be used to amplify or to modulate ultra high frequency currents. Another object is in the provision o means, in an ultra high irequency amplier, for focusing electrons upon dierent portions of a resonant output circuit asa function oi the input currents whereby amplidcation is obtained. Aincharacteristics of the invention. Similar refer- 4ence characters indicate similar elements.

1 other object is to provide means for modulating ultra high frequency oscillations by directing 30 Referring to Fig. l, if a pair of hollow cylinders o and b are suitably polarized, an electric lens will be formed. The curved lines C indicate the field through which are passed the electrons Vto be focused. The local lengths f1 and f2 are indi-I cated by the equation l fr Va where va and vb are; respectively, the potentials 'of the cylinders. 'As the ratio of the-.cylinder the lens will be produced. Under the inuence of such a lens, the passing electrons will cover a variable area, at a iixed distance from the lens', as the focus changes.

One application of the variable electric lens to an ultra high frequency device is illustrated in Fig. 2. Within an evacuated envelope l are mounted an electron gun 3, a ilrst hollow cylindrical electrode 5, a second hollow cylindrical electrode l, a third hollow cylindrical electrode a, 'and an output circuit il; The three hollow cylindrical electrodes form an electron lens in which the center electrode is connected through a transformer secondary winding i3 and a biasing winding l5 to ground. The primary winding il is connected to a source of signals to be ampliiled or applied to modulate an ultra high frequency oscillation as hereinafter described.

The output circuit is preferably of the concentric line type and includes a pair of concenf.

by means of a battery 23. The output connectionmay be made by coupling to the line or by a con- 'ductive connectiontc points of suitable impedance between the inner and outer conductors.

The output circuit may include a feedback connection 25. This connection consists of a tuned circuit 'lwhich may be connected to the rst cylindrical electrode t, or other electrode intermediate theoutput circuit and the gun 3. The

tuned circuit is coupled to the output circuit il by 'a primary winding 29 and a connecticut! to the inner electrode-of the output circuit. The feedback circuit, which may be ofthe concentric line type; is used to establish regeneration or ultra high frequency oscillations. If no regeneration or self-oscillation is required,V the feedback circuit may be eliminated.

` The mode of operation is as follows: Electrons from the electron gun 3 are directed through the several cylindrical electrodes 5, l, 9 toward the concentric electrodes I9, 2l. The lens is adljusted by varying the bias l5 until the electrons are focused onthe innerxelectrode I9 in the absence of signals. The transformer I3, l1 connections are acusted so that the potential of an applied signal will change the focus of the-lens vand will cause some of the electrons to impinge upon the outer electrode 2 I The adjustment may be made so that an applied signal of one polarity will focus the electrons on the inne'i` electrode, and the signal of opposite polarity will focus the eeeeeev faces, means for directing electrons from eeid source through seid lens upon said surfaces, and

means for varying the focus of said lens so thee said electrons alternately impinge en seid sun faces and pass through said'aperture.

7. An electronic device for generating ulm high l.'.ec1uei1cv petentlals including in eembine tion, e, source of electrons, en output @mme in l @leiding eiectecee upon which. electrons from eeie seme are impinged. en electric lens of veri-feme Eems e .ew 'ft between seid source end seid eiee'ces, end meems for feeding' energy from gemoeten?, circuit@ seid lens weer? the e1ec= esame @sawing :inem seid source thereby te estebiien meh requeney ceciiieticns.

@Neef G. mme. 

